There is nothing like the fresh smell of a spring morning, unless, during the night, a skunk skulked about your neighborhood. The striped skunk is armed with just a teaspoon of odoriferous oil in its two anal glands, but a little bit goes a long way.
When I was in junior high, I was hit with a burst of spray from a skunk at close range. I can attest that at high concentrations it causes nausea at first. It also acts like tear gas, causing watering eyes and a running nose. Oh, and your mother will most definitely make you take your clothes off outside and throw them out. If you’re lucky, she’ll let you back in after a series of home remedies, which never seem to fully cure the stench.
Skunk oil research has been going on for over a century as scientists have tried to determine what makes the stuff so potent that it can drive a bear away. Way back in 1896, Thomas Aldridge at Johns Hopkins University showed that humans could detect the smell at just 10 parts per billion, the equivalent to detecting just one drop of it diluted into a medium-sized, backyard swimming pool. More recently, William Wood, a chemist from Humboldt State University, pointed out that a number of chemicals have been incorrectly attributed to skunk oil over the years, and his work has now given us a fairly complete understanding of the chemical compounds and how to neutralize them.
The scent-gland secretion is a yellow oil composed primarily of volatile compounds known as thiols, and their derivatives. (A thiol is a compound distinguished by its sulfur-hydrogen bond.) Most of us immediately recognize the smell of ethanethiol, a common thiol that’s added to propane so we can easily smell any leaks. Another thiol creates the “skunky” smell of beer after it has been exposed to ultraviolet light.
The thiol derivatives present in skunk oil are not particularly odoriferous, but they are easily converted to far more potent thiols when they react with water. For weeks after I was sprayed, I would give off the faint smell of skunk at basketball practice. Perhaps the thioacetate derivatives trapped in my hair reacted with the moisture from my sweat. I don’t remember, but I wonder if my defenders backed off a bit affording me more scoring opportunities. The power of thiols.
Many people believe that tomato juice will neutralize the odor of a skunk, but human olfactory fatigue is a better explanation for the apparent disappearance of the odor. I could hardly smell the odor on my body after a few hours, but when a new nose came into range, its owner squealed with disgust. A tired nose will smell the tomatoes rather than the skunk.
You can neutralize the offensive thiols in skunk spray with the sulfonic acids found in most detergents. Oxidizers such as hydrogen peroxide and baking soda are mild enough to be used on pets, although they may create interestingly colored hair for some. For washing down your deck or trash can, try liquid laundry bleach.
The smell is certainly memorable. Even decades later, the thought of that moment when the skunk turned and sprayed almost turns my stomach and brings tears to my eyes again. The skunks are reluctant to use it, though. With only enough for a half dozen sprays at most, and a 10-day period to manufacture more, skunks will only spray if they absolutely have to. In an attempt to avoid spraying, skunks often give warning. First, they show their striped white back to warn you. This is followed by threat behaviors, like stomping with both front feet, sometimes charging forward, and then edging backwards dragging their feet and hissing. If all this fails, watch out.
Each spray gland has a nipple, and skunks can aim and direct the spray using highly coordinated muscles. A skunk can spray up to 25 feet and hit something fairly accurately up to 7 feet away. When there is a target, they can direct a fine stream right at the victim’s face. When being chased, a skunk will instead emit a foul cloud for the predator to run into.
There is one predator that remains undeterred by the odiferous oil, the great-horned owl. The small size of the olfactory lobes in their brains suggests that they have a very poor sense of smell. Some individual owls can downright stink of skunk, a common complaint among wildlife rehabilitation workers. Their nests can even smell of their musky meals. But larger-lobed mammals quickly learn to avoid the white stripe in the night.
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